As various multimedia services such as digital TV, IPTV (Internet Protocol Television), VOD (Video On Demand), etc. and the technology for enjoying the multimedia services are developed, among user devices capable of freely accessing multimedia contents such as digitized video, graphic, audio, etc., most of all, a growing need for a mobile terminal exists. To meet the growing need, recently, the technology of sharing data via wired or wireless communication, the display mirroring technology of sharing a screen image via the wired or wireless communication, etc. are adopted at user devices.
In order to perform the display mirroring, the smooth data transmission between remotely positioned user devices is required. Currently, the mirroring technology has unilateral directionality between the user devices depending on the type of the transmitted data. Concretely, if a head unit of a vehicle and a mobile terminal are mirrored, the data related to the touch or operation of the head unit is transmitted to the mobile terminal and the screen image data of the mobile terminal is transmitted to the head unit. And, the sound data of the mobile terminal is transmitted unilaterally to only the head unit. Therefore, if the mobile terminal and the head unit are mirrored, the connection of the mobile terminal and the head unit through a separate Bluetooth channel is needed in order to use the telephone call service or the voice recognition service of the mobile terminal. However, it's quite cumbersome to connect the mobile terminal and the head unit via the separate Bluetooth channel.